A ligament is a piece of fibrous tissue which connects one bone to another within the body. Ligaments are frequently damaged (e.g., detached, torn or ruptured) as the result of injury or accident. A damaged ligament can impede proper stability and motion of a joint and cause significant pain. When ligaments are damaged, surgical reconstruction can be necessary, as the ligaments may not regenerate on their own. A damaged ligament can be replaced or repaired using various procedures, a choice of which can depend on a particular ligament to be restored and on the extent of the damage.
An example of a ligament that is frequently damaged as a result of injury, overexertion, aging and/or accident is the anterior cruciate ligament (ACL) that extends between a top of the tibia and a bottom of the femur. Another ligament that is often damaged and may need to be replaced is a posterior cruciate ligament (PCL). A damaged ACL or PCL can cause instability of the knee joint, arthritis, and substantial pain.
ACL repair typically includes the use of a ligament graft replacement procedure which usually involves drilling bone tunnels through the tibia and the femur. Then a ligament graft, which may be an artificial ligament or harvested graft, such as a tendon, is passed through a tibial portion of the tunnel (sometimes referred to as “the tibial tunnel”) across the interior of the joint, and up into a femoral portion of a tunnel (sometimes referred to as “the femoral tunnel”). One end of the ligament graft can then be secured in the femoral tunnel and another end of the graft is secured in the tibial tunnel, at the sites where the natural ligament attaches.
A common ligament reconstruction procedure involves using an autograft, which is a portion of the patient's own tendon that would replace the damaged natural ligament. The autograft is often a hamstring tendon, though other tendons can be used (e.g., a patellar tendon). The ligament graft can also be obtained from a donor (“allograft”).
Ligament augmentation and replacement procedures typically require preparation of a harvested ligament graft using various techniques to secure the graft for passing through the drilled tunnels and to strengthen the graft prior to fixation. The preparation may involve cleaning and measuring the graft, and then affixing sutures to free ends thereof. The thus prepared graft can be tensioned prior to being inserted into the femoral and tibial tunnels.
Sutures are affixed to one or both free ends of the graft to reinforce it. The reinforcement is intended to maintain the structural integrity of the graft and to allow the graft to be properly tensioned when it is inserted into a tunnel for an ACL or PCL graft reconstruction. Sutures are affixed to the graft so that free suture ends that extend from one or both ends of the graft (which can be folded in half for the procedure) are used to secure the graft either directly or indirectly.
Although various graft preparation techniques exist for use in orthopedic surgery, such as, for example, ACL reconstruction, many of the developed approaches have certain drawbacks. In some instances, graft preparation can be time consuming and tedious. Simpler and quicker techniques often do not provide sufficient strength of attachment of the suture of the graft and may thus cause excessive elongation of the graft when a load is applied thereto. In other instances, a graft preparation technique can negatively affect the structural integrity of the graft.
Accordingly, there is a need for improved graft constructs and techniques for preparing such graft constructs while maintaining the desired structural integrity of the graft.